Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH 02/10] staging: erofs: fix race when the managed cache is
 enabled
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC:     <devel@driverdev.osuosl.org>, <linux-erofs@lists.ozlabs.org>,
        Chao Yu <yuchao0@huawei.com>,
        LKML <linux-kernel@vger.kernel.org>, <weidu.du@huawei.com>,
        Miao Xie <miaoxie@huawei.com>
References: <20181120143425.43637-1-gaoxiang25@huawei.com>
 <20181120143425.43637-3-gaoxiang25@huawei.com>
 <20181122101711.GA3189@kroah.com>
From:   Gao Xiang <gaoxiang25@huawei.com>
Message-ID: <55aed87f-196e-9048-6aae-db09bc497664@huawei.com>
Date:   Thu, 22 Nov 2018 18:42:52 +0800
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101
 Thunderbird/52.3.0
MIME-Version: 1.0
In-Reply-To: <20181122101711.GA3189@kroah.com>
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Greg,

On 2018/11/22 18:17, Greg Kroah-Hartman wrote:
> Any specific reason why you are not using the refcount.h api instead of
> "doing it yourself" with atomic_inc/dec()?
> 
> I'm not rejecting this, just curious.

As I explained in the previous email,
Re: [PATCH 04/10] staging: erofs: fix `erofs_workgroup_{try_to_freeze, unfreeze}'

we need such a function when the value is >= 0, it plays as a refcount,
but when the refcount == EROFS_LOCKED_MAGIC (<0, but not 0 as refcount.h),
and actually there is no need to introduce a seperate spinlock_t because
we don't actually care about its performance (rarely locked). and
the corresponding struct is too large for now, we need to decrease its size.

Thanks,
Gao Xiang

> 
> thanks,
> 
> greg k-h